The present invention relates generally to couplings for shafts and more particularly to a coupling utilizing a first shaft having an internal frusto-conical surface and a second shaft having an externally splined end.
In the past, gears were mounted on shafts by means of two frusto conical surfaced parts which were drawn together to accomplish radial expansion of the outer part for frictional holding in the gear and radial contraction of the inner part for frictional holding on the shaft. To aid disassembly of the parts, the frusto-conical surfaces were coated with a low coefficient of friction material such as Teflon (TM) and a locking bar was inserted to prevent relative movement of the frusto-conical surfaces. While the above design was sufficient for most torque applications, where a zero backlash fit is required between two shafts because of high frequency torque variations around 300 hertz, accompanied by severe torque reversals, the design is insufficient and slip will occur which will culminate in the destruction of the shafts or the mechanisms connected thereto.